SDLP leader Colum Eastwood said he has received death threats after naming Soldier F in the House of Commons.
The Foyle MP used parliamentary privilege to name the former British soldier accused of murdering two men during Bloody Sunday on Tuesday.
The veteran cannot be named for legal reasons.
Parliamentary privilege enables MPs to say whatever they wish in the House of Commons without fear of being sued for defamation.
On Wednesday, the Speaker Sir Lindsay Hoyle said Mr Eastwood had “broken no rules” because his comments were made during consideration of legislation and therefore the sub judice rule did not apply.
Sub judice, when in operation, aims to prevent MPs or Lords from referring to a current or impending court case to avoid possibly influencing the legal outcome of the case.
On Friday, Mr Eastwood revealed he has received death threats online and via email.
“It is not nice, particularly when you have a family,” he told the BBC.
“I did what I thought was right on behalf of the Bloody Sunday families. Those people have faced a whole lot worse than death threats.”
The Police Service of Northern Ireland (PSNI) has confirmed it is looking into the threats.
A spokesman said: “Police received a complaint that threatening and offensive comments had been made online yesterday, Thursday 15 July.
“Police enquiries are ongoing into this matter.”
Soldier F has been facing charges of murdering James Wray and William McKinney on Bloody Sunday in Londonderry in January 30 1972, when troops opened fire on civil rights demonstrators in the city’s Bogside, killing 13 people.
A legal challenge to the decision to withdraw proceedings against Soldier F is ongoing.